Discovery and antiproliferative evaluation of new quinoxalines as potential DNA intercalators and topoisomerase II inhibitors

In continuation of our previous work on the design and synthesis of topoisomerase II (Topo II) inhibitors and DNA intercalators, a new series of quinoxaline derivatives were designed and synthesized. The synthesized compounds were evaluated for their cytotoxic activities against a panel of three cancer cell lines (Hep G‐2, Hep‐2, and Caco‐2). Compounds 18b, 19b, 23, 25b , and 26 showed strong potencies against all tested cell lines with IC₅₀ values ranging from 0.26 ± 0.1 to 2.91 ± 0.1 µM, comparable with those of doxorubicin (IC₅₀ values ranging from 0.65 ± 0.1 to 0.81 ± 0.1 µM). The most active compounds were further evaluated for their Topo II inhibitory activities and DNA intercalating affinities. Compounds 19b and 19c exhibited high activities against Topo II (IC₅₀ = 0.97 ± 0.1 and 1.10 ± 0.1 µM, respectively) and bound the DNA at concentrations of 43.51 ± 2.0 and 49.11 ± 1.8 µM, respectively, whereas compound 28b exhibited a significant affinity to bind the DNA with an IC₅₀ value of 37.06 ± 1.8 µM. Moreover, apoptosis and cell‐cycle tests of the most promising compound 19b were carried out. It was found that 19b can significantly induce apoptosis in Hep G‐2 cells. It has revealed cell‐cycle arrest at the G2/M phase. Moreover, compound 19b downregulated the Bcl‐2 levels, indicating its potential to enhance apoptosis. Furthermore, molecular docking studies were carried out against the DNA–Topo II complex to examine the binding patterns of the synthesized compounds.     

Acute and subacute oral toxicity of copper oxide nanoparticles in female albino Wistar rats

The extensive use of copper oxide nanoparticles (CuO‐NPs) in various industries and their wide range of applications have led to their accumulation in different ecological niches of the environment. This excess exposure raises the concern about its potential toxic effects on various organisms including humans. However, the hazardous potential of CuO‐NPs in the literature is elusive, and it is essential to study its toxicity in different biological models. Hence, we have conducted single acute dose (2000 mg/kg) and multiple dose subacute (30, 300 and 1000 mg/kg daily for 28 days) oral toxicity studies of CuO‐NPs in female albino Wistar rats following OECD guidelines 420 and 407 respectively. Blood analysis, tissue aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acetylcholinesterase, superoxide dismutase, catalase, lipid malondialdehyde and reduced glutathione assays, and histopathology of the tissues were carried out. The higher dose treatments of the acute and subacute study caused significant alterations in biochemical and antioxidant parameters of the liver, kidney and brain tissues of the rat. In addition, histopathological evaluation of these three organs of treated rats showed significantly high abnormalities in their histoarchitecture when compared to control rats. We infer from the results that the toxicity observed in the liver, kidney and brain of treated rats could be due to the increased generation of reactive oxygen species by CuO‐NPs.     

Towards improved diagnosis of von Willebrand disease: Comparative evaluations of several automated von Willebrand factor antigen and activity assays

Introduction

von Willebrand disease (VWD) is reportedly the most common bleeding disorder and arises from deficiency and/or defects of von Willebrand factor (VWF). Laboratory diagnosis and typing has important management implications and requires a wide range of tests, including VWF activity and antigen, and involves differential identification of qualitative vs quantitative defects.

Methods

We have assessed several VWF antigen and activity assays (collagen binding [VWF:CB], ristocetin cofactor [VWF:RCo] and the new Siemens INNOVANCE assay [VWF:Ac], employing latex particles and gain of function recombinant glycoprotein Ib to facilitate VWF binding and agglutination without need for ristocetin) using different instrumentation, including the new Sysmex CS-5100, with a large sample test set (n = 600). We included retrospective plus prospective study designs, and also evaluated desmopressin responsiveness plus differential sensitivity to high molecular weight VWF.

Results

VWF:Ag and VWF:RCo results from different methods were respectively largely comparable, although some notable differences were evident, including one high false normal VWF:Ag value (105 U/dL) on a type 3 VWD sample, possibly due to heterophile antibody interference in the latex-based CS-5100 methodology. VWF:Ac was largely comparable to VWF:RCo, but VWF:CB showed discrepant findings to both VWF:RCo and VWF:Ac with some patients, most notably patients with type 2M VWD.

Conclusions

(a) VWF:Ag on different platforms are largely interchangeable, as are VWF:RCo on different platforms, except for occasional (some potentially important) differences, and manufacturer recommended methods may otherwise require some assay optimization; (b) VWF:RCo and VWF:Ac are largely interchangeable, except for occasional differences that may also relate to assay design (differing optimizations); (c) VWF:CB provides an additional activity to supplement VWF:RCo or VWF:Ac activity assays, and is not interchangeable with either.     

Lipoprotein status among urban populations in Bangladesh

ObjectiveSerum lipoprotein is the most important predictor for microvascular diseases, and may be influenced by rapid urbanization. Currently available data are limited, particularly regarding age-specific lipoprotein status in urban Bangladeshi populations.MethodsBlood lipoprotein levels of 51,353 male and female individuals primarily residing in urban Bangladesh were analyzed. De-identified data (collected between January 2005 and December 2011) were extracted from the Clinical Biochemistry Laboratory Data Archive of International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). For analyses, six age categories were created: (i) <20 years, n = 481; (ii) 20–29 years, n = 1602; (iii) 30–39 years, n = 7272; (iv) 40–49 years, n = 13,582; (v) 50–59 years, n = 15,890; and (vi) 60 years and more, n = 12,526.ResultsMean serum levels of TC, LDL, TG, LDL:HDL and TC:HDL were significantly higher among adults 30–39 years old compared to other age groups, regardless of sex. The proportion of high TC and LDL from 2005 to 2011 among individuals aged 30–39 years old varied widely (p < 0.01 for trend and all pairwise tests).Conclusion30–39 years old individuals had higher concentration of lipoprotein, which increases microvascular disease risk. Further population-based studies are needed to validate our observations in rural areas of Bangladesh.     

Elevated IgG levels against specific bacterial antigens in obese patients with diabetes and in mice with diet-induced obesity and glucose intolerance

High fat diets increase the risk for insulin resistance by promoting inflammation. The cause of inflammation is unclear, but germfree mouse studies have implicated commensal gut bacteria. We tested whether diet-induced obesity, diabetes, and inflammation are associated with anti-bacterial IgG. Blood from lean and obese healthy volunteers or obese patients with diabetes were analyzed by ELISA for IgG against extracts of potentially pathogenic and pro-biotic strains of Escherichia coli (LF-82 and Nissle), Bacteroides thetaiotaomicron, and Lactobacillus acidophilus, and for circulating tumor necrosis factor α (TNFα). C57Bl/6 mice were fed low- or high-fat diets (10% or 60% kcal from fat) for 10 weeks and tested for anti-bacterial IgG, bodyweight, fasting glucose, and inflammation. Obese diabetic patients had significantly more IgG against extracts of E. coli LF-82 compared with lean controls, whereas IgG against extracts of the other bacteria was unchanged. Circulating TNFα was elevated and correlated with IgG against the LF-82 extract. Mice fed high-fat diets had increased fasting glucose levels, elevated TNFα and neutrophils, and significantly more IgG against the LF-82 extracts. Diabetes in obesity is characterized by increased IgG against specific bacterial antigens. Specific commensal bacteria may mediate inflammatory effects of high-fat diets.